diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index 6ac12e4e1387..0a38fa317305 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -542,6 +542,7 @@
   ./services/monitoring/kapacitor.nix
   ./services/monitoring/loki.nix
   ./services/monitoring/longview.nix
+  ./services/monitoring/mackerel-agent.nix
   ./services/monitoring/monit.nix
   ./services/monitoring/munin.nix
   ./services/monitoring/nagios.nix
diff --git a/nixos/modules/services/monitoring/mackerel-agent.nix b/nixos/modules/services/monitoring/mackerel-agent.nix
new file mode 100644
index 000000000000..7046de9d403c
--- /dev/null
+++ b/nixos/modules/services/monitoring/mackerel-agent.nix
@@ -0,0 +1,111 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.mackerel-agent;
+  settingsFmt = pkgs.formats.toml {};
+in {
+  options.services.mackerel-agent = {
+    enable = mkEnableOption "mackerel.io agent";
+
+    # the upstream package runs as root, but doesn't seem to be strictly
+    # necessary for basic functionality
+    runAsRoot = mkEnableOption "Whether to run as root.";
+
+    autoRetirement = mkEnableOption ''
+      Whether to automatically retire the host upon OS shutdown.
+    '';
+
+    apiKeyFile = mkOption {
+      type = types.path;
+      default = "";
+      example = "/run/keys/mackerel-api-key";
+      description = ''
+        Path to file containing the Mackerel API key. The file should contain a
+        single line of the following form:
+
+        <literallayout>apikey = "EXAMPLE_API_KEY"</literallayout>
+      '';
+    };
+
+    settings = mkOption {
+      description = ''
+        Options for mackerel-agent.conf.
+
+        Documentation:
+        <link xlink:href="https://mackerel.io/docs/entry/spec/agent"/>
+      '';
+
+      default = {};
+      example = {
+        verbose = false;
+        silent = false;
+      };
+
+      type = types.submodule {
+        freeformType = settingsFmt.type;
+
+        options.host_status = {
+          on_start = mkOption {
+            type = types.enum [ "working" "standby" "maintenance" "poweroff" ];
+            description = "Host status after agent startup.";
+            default = "working";
+          };
+          on_stop = mkOption {
+            type = types.enum [ "working" "standby" "maintenance" "poweroff" ];
+            description = "Host status after agent shutdown.";
+            default = "poweroff";
+          };
+        };
+
+        options.diagnostic =
+          mkEnableOption "Collect memory usage for the agent itself";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [ mackerel-agent ];
+
+    environment.etc = {
+      "mackerel-agent/mackerel-agent.conf".source =
+        settingsFmt.generate "mackerel-agent.conf" cfg.settings;
+      "mackerel-agent/conf.d/api-key.conf".source = cfg.apiKeyFile;
+    };
+
+    services.mackerel-agent.settings = {
+      root = mkDefault "/var/lib/mackerel-agent";
+      pidfile = mkDefault "/run/mackerel-agent/mackerel-agent.pid";
+
+      # conf.d stores the symlink to cfg.apiKeyFile
+      include = mkDefault "/etc/mackerel-agent/conf.d/*.conf";
+    };
+
+    # upstream service file in https://git.io/JUt4Q
+    systemd.services.mackerel-agent = {
+      description = "mackerel.io agent";
+      after = [ "network-online.target" "nss-lookup.target" ];
+      wantedBy = [ "multi-user.target" ];
+      environment = {
+        MACKEREL_PLUGIN_WORKDIR = mkDefault "%C/mackerel-agent";
+      };
+      serviceConfig = {
+        DynamicUser = !cfg.runAsRoot;
+        PrivateTmp = mkDefault true;
+        CacheDirectory = "mackerel-agent";
+        ConfigurationDirectory = "mackerel-agent";
+        RuntimeDirectory = "mackerel-agent";
+        StateDirectory = "mackerel-agent";
+        ExecStart = "${pkgs.mackerel-agent}/bin/mackerel-agent supervise";
+        ExecStopPost = mkIf cfg.autoRetirement "${pkg.mackerel-agent}/bin/mackerel-agent retire -force";
+        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
+        LimitNOFILE = mkDefault 65536;
+        LimitNPROC = mkDefault 65536;
+      };
+      restartTriggers = [
+        config.environment.etc."mackerel-agent/mackerel-agent.conf".source
+      ];
+    };
+  };
+}
diff --git a/pkgs/servers/monitoring/mackerel-agent/default.nix b/pkgs/servers/monitoring/mackerel-agent/default.nix
new file mode 100644
index 000000000000..c5548fafd348
--- /dev/null
+++ b/pkgs/servers/monitoring/mackerel-agent/default.nix
@@ -0,0 +1,42 @@
+{ stdenv, lib, buildGoModule, fetchFromGitHub, makeWrapper, iproute, nettools }:
+
+buildGoModule rec {
+  pname = "mackerel-agent";
+  version = "0.69.3";
+
+  src = fetchFromGitHub {
+    owner = "mackerelio";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0jkvqqzk6wyjsdsmn2l2cdw8pjqzswlqb9p492czhgrfy065lrqp";
+  };
+
+  nativeBuildInputs = [ makeWrapper ];
+  checkInputs = lib.optionals (!stdenv.isDarwin) [ nettools ];
+  buildInputs = lib.optionals (!stdenv.isDarwin) [ iproute ];
+
+  vendorSha256 = "0kjky2mhs6dapnr4xpjpnbibp6y8r320igddplynsfsp8vwrfp7m";
+
+  subPackages = [ "." ];
+
+  buildFlagsArray = ''
+    -ldflags=
+    -X=main.version=${version}
+    -X=main.gitcommit=v${version}
+  '';
+
+  postInstall = ''
+    wrapProgram $out/bin/mackerel-agent \
+      --prefix PATH : "${lib.makeBinPath buildInputs}"
+  '';
+
+  doCheck = true;
+
+  meta = with lib; {
+    description = "System monitoring service for mackerel.io";
+    homepage = "https://github.com/mackerelio/mackerel-agent";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ midchildan ];
+    platforms = platforms.all;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 65e7818736d3..5a3696909418 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -16872,6 +16872,8 @@ in
 
   labelImg = callPackage ../applications/science/machine-learning/labelimg { };
 
+  mackerel-agent = callPackage ../servers/monitoring/mackerel-agent { };
+
   mailman = callPackage ../servers/mail/mailman/wrapped.nix { };
 
   mailman-rss = callPackage ../development/python-modules/mailman-rss { };